After poking around with this, it is the sensors that are attached to PA2's that disappear. Is this the USB communication issue I've been reading about? If so it looks like it hasn't been fixed. I'm running Beta 14.
I have the same problem - from time to time all sensors from PA2 Ultra dissappear from my Aquaero 5 XT. I'm running Beta 14.
However, if you connect via old Aquasuite, the PA2 is operational and all sensors are showing correct readings.
To mitigate need a complete power down of the PC.
BTW is there a way of rebooting Aquaero via software?
Cheers,
Rafal